Category : Files from Magazines
Archive   : MAY91.ZIP
Filename : 2N05033A

/*
* File: CDRom.C
* Purpose: Contains the CDROM Device Driver
* specific commands
*/

#include "device.h"


/* External Functions */
int NetSend (FPTR buf, int size, BYTE session);
int NetReceive (FPTR buf, int size, BYTE session);

/* External Data */
extern BYTE localSession;


/*
* ReadLong : Read CDROM sectors
* Transfer the read request to the server.
* Receive the update header and the data
* into the dta. Cooked mode (0) reads handle
* 2048 bytes per sector, raw mode (1) handle
* 2352.
*/
int ReadLong (RH_CDREAD far *rh)
{
int ret;

/** Send request to server **/
ret = NetSend (rh, rh->rh.length,
localSession);

/** Get the header results back **/
if (!ret)
ret = NetReceive (rh, rh->rh.length,
localSession);

/** See if DTA read to come in **/
if (!ret) {
if (rh->rh.status != 0x100)
/** Read failed **/
return rh->rh.status;

/** Okay to get data **/
ret = NetReceive (rh->dta,
(2048+304*rh->readMode)*rh->count,
localSession);
}

if (ret)
/** An error occurred somewhere **/
return DEV_ERROR | DEV_EREAD | DEV_DONE;

else
return DEV_DONE;
}

/*
* ReadPrefetch : Prefetch CDROM sectors
* No read or data transfer is required. This
* command is advisory only. Therefore, just
* say it happened.
*/
int ReadPrefetch (RH_CDREAD far *rh)
{
return DEV_DONE;
}

/*
* Seek : Seek to CDROM sector
* Mandatory seek to given sector. Only
* the request header must travel to and
* from the server.
*/
int Seek (RH_CDSEEK far *rh)
{
int ret;

/** Send request to server **/
ret = NetSend (rh, rh->rh.length,
localSession);

/** Get the header results back **/
if (!ret)
ret = NetReceive (rh, rh->rh.length,
localSession);

if (ret)
/** An error occurred somewhere **/
return DEV_ERROR | DEV_EREAD | DEV_DONE;

if (rh->rh.status != 0x100)
/** Seek failed **/
return rh->rh.status;
else
return DEV_DONE;
}